1. Processes used to for metallic materials

2. Hundreds of processes to shape or form metallic materials
Many have been around for thousands of years
Choosing a process depends on:
Type of metal
Production volume
Cost
Desired properties of finished part

3. Forging Hand forging Dates back to 4000B.C.
How blacksmiths shape metal
Heat until cherry red
Hammer against an anvil to get desired shape
Used by crafters working with wrought iron today

4. Applied to several processes
Forging
Applied to several processes
Metal shaped by heavy presses and drop-forging hammers forcing heated metal into shape
Little material is lost
Shape is changed by repositioning metal during the process
Grain of metal can be controlled making stronger/tougher part
Used to make: bolts (without threads), rivets, connecting rods, gears

5. Simplest of all forging
Open-Die Forging
Simplest of all forging
Heated workpiece is formed between flat dies that compact
Dies don’t completely enclose
Time consuming
Quality depends on skill
Limited application in high volume production

6. Cannot shape the part completely
Creates flashing
Material that squeezes out, excess
Cannot shape the part completely
Excess material has to be removed by machining
Forged gear blanks can have up to 70% waste
Teeth have to be machined

7. Closed-Die Forging
Produces a near net shape part (close to final shape)
Reduced waste
Preheated metal completely encompassed by the die set
Upper die repeatedly hammers the material, causing it to flow until it conforms to the shape of the die cavity

8. Majority of commercial forging
More stock used to completely fill the die
Dies can be made with a gutter (groove)
Gutter is area for excess material to go

9. Coining Squeezing metal while it is confined in a closed set of dies
Requires high pressure and precision dies
Used to make coins and medallions
Small details
Causes metal to move from thinner to thicker areas

10. Blank is placed in die
Movable punch cold works the material
Can form fine detail
Pressures as high as 200,000 psi

12. Rotary Forming Processes
Uses rollers to squeeze and shape metal

13. Any ductile metal can be formed without heat
Roller forming
Any ductile metal can be formed without heat
Forms straight stock into nearly any imaginable shape
No dies
Rollers progressively squeeze stock into desired shape
Rollers grip and form, each set makes a small shape change
Thickness remains fairly constant
Only shape changes

14. Roller forming is a fast process Often combined with other processes
Roller operation feeds into:
cutting operation
welding operation
Another forming operation

15. Different types based on roller positions and number of rollers:
Roll Bending
Used to bend bar, rod, tube, angle and channel stock into circular, curved and cylindrical shapes
Different types based on roller positions and number of rollers:
Roll bender
Two-roll machine
Three-roll double-pinch machine
Stretch forming

16. Thread Rolling Forms threads on fasteners
Chipless cold-forming process (no waste)
Blank (material) is rolled against grooved dies

17. Swaging AKA rotary swaging, radial forging Uses 2 or 4 opposing dies
Dies strike material repeatedly

18. Extrusion Compresses metal beyond its elastic limit
Continuous pressure
Like squeezing toothpaste

19. Direct extrusion
Ram forces stock through the die opening

20. Stationary mandrel extrusion
Make hollow tubing
Ram is attached to stationary mandrel
Forces material through die opening from inside the material

21. Impact extrusion
Used to make collapsible tubes
Soft materials
Slug placed in a die cavity then struck by a punch
Metal flows back around the punch